Negative pressure pumps are used in vehicles, for example to provide negative pressure for a brake servo. The pump can be arranged laterally on the cylinder head of a vehicle engine and driven by a cam shaft, as has been typical for a long time. Due to design space restrictions and also in order to reduce the specific design size, the negative pressure pump has in more recent times been arranged in the oil sump, in tandem arrangement with a lubricating oil pump. Due to the relatively great demands made on the strength of seal, it has hitherto been typical to provide a seal by means of an O-ring seal or a profiled form seal. The seal is intended to prevent air from being suctioned from the environment. In pumps attached to the outside of the engine, it is also intended to prevent oil from escaping. If it is arranged in the oil sump, it is no longer mandatory for the oil seal of the system to the outside to be absolute. In practice, the seal only then serves to avoid air being suctioned.
The sealing elements, such as for example O-ring seals and profiled form seals, are produced separately and inserted into a sealing groove of a housing part of the gas pump which encloses the delivery chamber or placed onto a front face of the housing part. They are secured on the housing part for and while being assembled. The sealing elements generate costs which, in particular in mass production such as is typical in vehicle production, can no longer be overlooked. Over the service life of the pump, the strength of seal will also suffer due to material degradation of the sealing elements.
Gas pumps which are embodied as vane cell pumps are for example disclosed in US 2012/0060683 A, U.S. Pat. No. 3,326,456 A and WO 2007/003215 A1.